I like to read course material on Kindle. I merge all lecture slides with Automator and then send them to my Kindle email. Earlier, I have used Readle's Documents app (a spinoff of PDF Expert) where I had a search. If no OCR, then DjVU Reader in OS X to PDF and then ABBYY's FineReader Express to add OCR. Kindle has one failure with this: it cannot search despite the OCR of the PDF. It needs to be in a correct format: PDF is not a correct format but some Kindle's own format.

So does there exist any app in OS X to make material such as lecture slides suitable for reading in Kindle? Lecture slides are technical containing mathematical formulae.

It requires many steps already over OS X with Automator, DjVU Reader, ABBYY -- to make searchable in one way. I am trying to find an easy way with Kindle and Apple OS X.

Amazon's own "Send to Kindle" has the conversion in options but it is extremely poor with technical writing, it does some sort of HTML conversion making the text totally unreadable. This is the same thing as Calibre so not good...
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hhhMar 8 '13 at 22:55

+1 Calibre is a very useful in finding the meta-data about books and in uploading to iTunes over different iDevices. This does not solve the problem in question but alleviates it -- I have started to use it and it is pretty cool :)
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hhhMar 11 '13 at 19:09

Reading technical material on Kindle pretty much requires the books bought as Kindle format. This is because technical writing with mathematical formulae look awful after the conversion from PDF to, let say, to Kindle format or HTML. Even the bought books covering technical areas can look awful in Kindle or very impractical because of low screen-updating. Now this is of course different if you use iPad's Kindle but still the conversion is the key problem. There may be some good conversion from PDF to HTML. I suggest to search over things such as Mathjax.org because it is the tool used to display Mathematics for example in Stackexchange.

Now there are other ways. The trick is not to convert the PDF but keep them as PDF or convert DjVU into PDFs after OCR-addition with tools such as ABBYY or Adobe Acrobat Pro. iBook is freaking cool if you have OS X. You can syncronize all of your course material from iTunes to other iDevices. I just found it so now using iPad/iPhone instead of Kindle! Then again if you don't need to read technical material, Kindle can be very good-reading device particularly to your eyes. Please, also look at Nook reading-device -- Kindle is not the only device around.

K2pdfopt is an application that attempts to re-format PDF files for a smaller (e-reader) viewing screen and does a good job of not mangling/losing figures and mathematical formulas. It has an OS/X binary. Cross reference this e-books question.

Basically you use this to convert to a small screen friendly pdf, then use one of the other mentioned converters to convert to .mobi